The not-for-profit hospital system owned by Trinity Health filed an application with the Illinois Health Facilities and Services Review Board to take over the west suburban Chicago hospital. If regulators approve the deal, the sale would close March 1.

The deal reflects the market trend to increase scale quickly, in an effort to add more patients and doctors to treat them. The approach is designed to spread the financial risk associated with taking on the sickest people, since insurers are increasingly paying hospitals for the quality provided, rather than the amount of care.